Plant Stress Research Articles

Ethylene antagonizes ABA and inhibits stomatal closure and chilling tolerance in rice.

Chilling stress restricts the geographical distribution of rice and severely impacts its growth and development, ultimately reducing both yield and quality. The plant hormone ethylene is involved in plant stress responses; however, its role in rice chilling tolerance has not been thoroughly explored. This study reveals that ethylene negatively regulates chilling tolerance in rice by antagonizing the chilling tolerance-promoting effects of abscisic acid (ABA). Treatment with ethylene or its biosynthetic precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), results in a reduced survival rate after chilling and delayed stomatal closure in response to chilling. There are two ethylene signaling-related Raf-like protein kinases, OsCTR1 and OsCTR2, which have overlapping functions in ethylene signaling; their loss-of-function mutants exhibit constitutive ethylene responses. The ctr1 ctr2 double mutant displays lower survival rates and slower stomatal closure under chilling stress compared to the wild type. In contrast, ABA treatment significantly enhances the survival rate of the wild type under chilling stress and promotes stomatal closure in response to chilling. Furthermore, ethylene inhibits the effects of ABA on chilling tolerance and stomatal closure. The ctr1 ctr2 double mutant fails to respond to external ABA treatment regarding stomatal closure and increased survival rate under chilling stress. In conclusion, our findings suggest that ethylene negatively regulates chilling tolerance in rice by inhibiting ABA-induced stomatal closure through the action of OsCTR1 and OsCTR2.

The Plant Growth-Promoting Ability of Alfalfa Rhizobial Strains Under Nickel Stress

The growth and nutrient balance of legumes can be disrupted in soils with increased nickel (Ni) concentrations. The inoculation of legumes with rhizobia, symbiotic nitrogen-fixing bacteria, can be used for the alleviation of trace metal stress in plants. This study evaluated the Ni tolerance of alfalfa rhizobia isolates and some plant growth-promoting traits in the presence of Ni: indole-3-acetic acid (IAA) production, Ni biosorption potential, and the effect of rhizobia on alfalfa (Medicago sativa L.) growth. The strains were characterized as Shinorhizobium meliloti, Sinorhizobium medicae, and Rhizobium tibeticum. In total, 70% of the tested strains tolerate up to 0.8 mM Ni, while 15% of the strains tolerate 1.2 mM Ni. The production of IAA was maintained in the presence of Ni until bacterial growth was stopped by raising the Ni concentration. Alfalfa seed germination is significantly reduced in the presence of 0.5 mM Ni, while a significant reduction in 10-day-old seedling length already occurs at a Ni concentration of 0.03 mM. In the plant experiment, when alfalfa was inoculated with rhizobial strains, nodulation was maintained up to 0.05 mM Ni, but a significant reduction in nodule number was detected at 0.01 mM Ni. At the concentration of 0.005 mM Ni, inoculation with 12 particular rhizobial strains significantly improved the number of nodules per plant, plant height, and root length, as well as plant shoot dry weight, compared to non-inoculated plants with Ni addition. However, higher concentrations caused a reduction in all of these plant growth parameters compared to the plants without Ni. The selected rhizobia strains showed a Ni biosorption capacity of 20% in the in vitro assay. The inoculation of alfalfa with effective rhizobial strains improves growth parameters compared to non-inoculated plants in the presence of certain concentrations of Ni.

Combined effects of gibberellin and vermiwash on the life history and antioxidant system of Phthorimaea absoluta (Meyrick) in tomato plants

Tomato (Lycopersicon esculentum Miller), is a globally important agricultural product, yet it is under significant threat from pests such as the tomato leaf miner, Phthorimaea absoluta (Meyrick) (Lepidoptera: Gelechiidae). This study investigates the combined effects of gibberellin and vermiwash treatment on the life history and antioxidant system of P. absoluta. Given the pest’s resistance to many chemical pesticides, alternative control methods are crucial. Gibberellins are plant growth hormones known for their role in plant development and stress responses, while vermiwash is a bio-fertilizer rich in nutrients and microbial agents. We applied gibberellin and vermiwash (GV treatment) to tomato plants and assessed the impact on P. absoluta developmental stages, reproduction, and enzymatic activities. Our results show significant differences in larval development times (32.06 ± 0.39) and survival rates (0.53 ± 0.09) between treated and control groups (27.38 ± 0.35 and 0.80 ± 0.07, respectively). The GV treatment prolonged the total lifespan of P. absoluta (44.31 ± 0.51) but reduced its intrinsic rate of increase (r) (0.086 ± 0.009) and finite rate of increase (λ) (1.090 ± 0.009). Enzymatic assays revealed altered antioxidant and detoxifying enzyme activities in treated larvae. This study suggests that gibberellin and vermiwash treatments could be incorporated into pest management strategies for sustainable tomato production.

Identification and functional analysis of Wall-Associated Kinase genes in Nicotiana tabacum

IntroductionWall-associated kinases (WAKs) are pivotal in linking plant cell walls to intracellular signaling networks, thereby playing essential roles in plant growth, development, and stress responses. MethodsThe bioinformatics analysis was employed to identify WAK genes in tobacco. The expression levels of NtWAK genes were assessed by qRT-PCR. The subcellular localization of WAK proteins was observed in tobacco cells and Arabidopsis protoplasts. Kinase activity of the WAK proteins was evaluated through in vitro assays. ResultsWe conducted a comprehensive genome-wide identification and analysis of the WAK gene family in tobacco (Nicotiana tabacum). A total of 44 WAK genes were identified in the tobacco genome, which were further classified into three distinct groups. Phylogenetic analysis comparing tobacco WAKs (NtWAKs) with Arabidopsis WAKs (AtWAKs) revealed species-specific expansion of these genes. The WAK proteins within each group displayed similar gene structures and conserved motif distributions. Promoter region analysis indicated that cis-elements of NtWAK genes are primarily involved in regulating plant growth and development, phytohormone signaling, and stress responses. Expression profiling under NaCl, PEG, and ABA treatments suggested that certain NtWAK genes may play key roles in modulating responses to abiotic stress. Three-dimensional structural predictions and subcellular localization analysis showed that NtWAK proteins from the three subgroups exhibit high cytoplasmic similarity and are primarily located to the plasma membrane. Kinase activity assay confirmed that they possess phosphorylation activity. DiscussionThis study represents the first genome-wide analysis of the WAK gene family in N. tabacum, laying the groundwork for future functional investigations.

Abscisic acid signaling gates salt-induced responses of plant roots

Soil salinity presents a dual challenge for plants, involving both osmotic and ionic stress. In response, plants deploy distinct yet interconnected mechanisms to cope with these facets of salinity stress. In this investigation, we observed a substantial overlap in the salt (NaCl)-induced transcriptional responses of Arabidopsis roots with those triggered by osmotic stress or the plant stress hormone abscisic acid (ABA), as anticipated. Notably, a specific cluster of genes responded uniquely to sodium (Na+) ions and are not regulated by the known monovalent cation sensing mechanism MOCA1. Surprisingly, expression of sodium-induced genes exhibited a negative correlation with the ABA response and preceded the activation of genes induced by the osmotic stress component of salt. Elevated exogenous ABA levels resulted in the complete abolition of sodium-induced responses. Consistently, the ABA insensitive snrk2.2/2.3 double mutant displayed prolonged sodium-induced gene expression, coupled with increased root cell damage and root swelling under high salinity conditions. Moreover, ABA biosynthesis and signaling mutants were unable to redirect root growth to avoid high sodium concentrations and had increased sodium accumulation in the shoot. In summary, our findings unveil an unexpected and pivotal role for ABA signaling in mitigating cellular damage induced by salinity stress and modulating sodium-induced responses in plant roots.

Impact of m6A Modification and Transcript Quantity on mRNA Composition in Plant Stress Granules.

Stress granules (SGs) are cytoplasmic structures that emerge in response to unfavorable environmental conditions. The mechanisms governing the accumulation of transcripts in SGs are only partially understood. Despite the recognized role of N6-methyladenosine (m6A) in plant transcriptome regulation, its impact on SGs' composition and assembly remains elusive. In Lupinus angustifolius, SGs display a distinctive bi-zonal structure comprising of a ring and a central area with differences in ultrastructure and composition. Subsequent to the transcriptome analysis, specific mRNA were chosen to investigate their localization within SGs and assess m6A levels. Transcripts of hypoxia-responsive genes (ADH1 and HUP7) showed significantly lower levels of m6A compared to housekeeping genes, but only ADH1 was absent in SGs. HUP7 mRNA, characterized by a low quantity of m6A, is present both in the SGs and cytoplasm, probably due to extremely high expression level. The m6A was observed only during the assembly of SGs. In mutants of Arabidopsis thaliana with reduced levels of m6A, ECT2 (reader of m6A) was not observed in SGs, and poly(A) RNA levels and the number of SGs were reduced. In summary, our findings demonstrate a limited impact of m6A modification on SGs assembly. However, the interplay between m6A modification and the overall transcript quantity in the cytoplasm appears to play a regulatory role in mRNA partitioning and assembly of SGs.

A Maize Calmodulin-like 3 Gene Positively Regulates Drought Tolerance in Maize and Arabidopsis

Drought stress is one of the important abiotic stresses that affects maize production. As an important Ca2+ sensor, calmodulin-like proteins (CMLs) play key roles in plant growth, development, and stress response, but there are a limited number of studies regarding CMLs in response to drought stress. In this study, a Calmodulin-like gene, namely ZmCML3, was isolated from maize (Zea mays L.). The coding sequence (CDS) of ZmCML3 was 474 bp and a protein of 158 aa which contains three EF-hand motifs. ZmCML3 was localized within the nucleus and plasma membrane. The expression of ZmCML3 was induced by polyethylene glycol (PEG) 6000, NaCl, methyl jasmonate (MeJA), and abscisic acid (ABA). Overexpression of ZmCML3 resulted in enhanced drought tolerance in maize through increasing proline (Pro) content and the activity of peroxide (POD) and superoxide dismutase (SOD). Meanwhile, ZmCML3 also positively regulated the expression of drought stress-responsive genes in maize under drought stress treatment. Taken together, ZmCML3 acts as a positive regulator in maize response to drought stress. These results will provide theoretical basis for breeding drought tolerance maize variety.

Ornithine enantiomers modulate essential oil yield and constituents and gene expression of monoterpenes synthase in Salvia officinalis under well-watered and drought stress conditions

The impact of drought stress on plant growth, development, and productivity presents a significant challenge in various environments worldwide. The exogenous application of polyamines as osmotically active materials plays a crucial role in enhancing plant tolerance to environmental stress. In this study, we examined the effects of L- and D-enantiomers of ornithine (0 and 1 mM) under both well-watered and drought stress conditions on the growth traits, essential oil (EO) yield, and composition, gene expression, and total phenolic and flavonoid content of Salvia officinalis. The experiment was designed as a factorial experiment using a completely randomized design with three replications. The results demonstrated that drought stress led to a decrease in plant biomass and an increase in EO content, chemical profiles of the EO, and total phenolic and flavonoid content compared to the respective control values. However, the exogenous supplementation of ornithine particularly D-ornithine resulted in enhanced stem, leaf, and total plant biomass, a 20% increase in EO content, and a 75% increase in yield. Additionally, these were increases of 11.76% in total phenol and 70%, 105.66%, and 114.28% in flavonoid content when compared to well-watered plants without ornithine supplementation. These improvements were strongly linked to growth enhancement, as evidenced by principal component analysis (PCA). The EO extracted from S. officinalis consisted of 22 compounds, primarily monoterpenes, including α-thujone (18.47–41.65%), camphor (15.05–25.17%), 1,8-cineole (10.12–21.6%), and β-thujone (6.23–21.2%). The percentage of these volatile compounds was found to be highest in D-ornithine-treated stressed plants compared to control conditions. The interaction between water availability and the application of D-ornithine and L-ornithine significantly influenced the expression of borneol diphosphate synthase (BS), sabinene synthase (SS), and cineole synthase (CS) under drought stress, with notable upregulation observed compared to normal growth conditions. Specifically, D-ornithine enhanced the expression of BS and SS by 45.29% and 113.63%, respectively, under drought stress, while both D-ornithine and DL-ornithine significantly increased CS expression. The present results suggest that D-ornithine may serve as a stress-protecting compound, increasing total phenol and flavonoids content, thereby enhancing the capacity of the antioxidant system and increasing EO compounds under drought stress.

Exogenous trehalose alleviates the inhibitory effects of salt and drought stresses in okra plants

Exogenous trehalose alleviates the inhibitory effects of salt and drought stresses in okra plants

Genome-wide identification and expression analysis of ZF-HD family in sunflower (Helianthus annuus L.) under drought and salt stresses

BackgroundSunflower (Helianthus annuus L.) is widely cultured in globally tropical and subtropical regions, with better resistance to various abiotic stresses as a model crop. Despite the fact that zinc finger-homeodomain (ZF-HD) genes play an important role in responding to plant growth, development and stress resistance across the multiple species, the evolutionary history and abiotic function of the ZF-HD gene family in sunflower remain largely unexplored.ResultsIn this study, we identified 15 HaZF-HD genes (designated as HaZF1–HaZF15) in the sunflower genome, and they were divided into MIF and ZHD subfamilies. The proteins from the same group were similar in conserved motifs and domains, such as motif 1 and motif 3, constituting the ZF domain, were almost existed in 15 HaZF-HD proteins. Motif 2 (HD domain) was specifically presented in the ZHD subfamily. Collinearity analysis revealed that 5 pairs of genes with fragment duplication contributed to the expansion of HaZF-HD gene family. The analysis of cis-acting element demonstrated that the response elements related the hormone response and abiotic/biotic stress were the most prevalent, followed by plant growth and development elements. In the tissue expression profile, HaZF-HD gene family had the highest expression in leaves and floral organs. Additionally, RNA-seq and RT-qPCR analysis revealed HaZF3 responded positively in the initial stage of drought stress, whereas a prompt and significant decrease of relative expression value in response to salt stress was showed in HaZF6 and HaZF9.ConclusionsOverall, this study enhances our comprehension of the function of ZF-HD genes in positive regulation of responsiveness to abiotic stress and provide key candidate genes for sunflower stress resistance breeding.

Composition and Biodiversity of Culturable Endophytic Fungi in the Roots of Alpine Medicinal Plants in Xinjiang, China

(1) Background: Endophytic fungi play an important role in plant growth and stress resistance. The presence of a special fungal taxon such as the dark septate endophytic (DSE) fungi in alpine environments is particularly important for plant resistance to environmental stresses. However, the composition of root endophytic fungi in different environments and between different host plants has not been well studied. (2) Results: A total of 408 culturable endophytic fungi were isolated from the roots of Saussurea involucrata and Rhodiola crenulata which were collected in 5 plots from the Tianshan and Karakoram Mountains of the Xinjiang region, belonging to 91 species, 54 genera, 31 families, and 3 phyla based on the morphological characteristics and molecular sequence. Among them, DSE fungi were the dominant group, accounting for 52.94%, and Leptodontidium orchidicola was the dominant species. In addition, we also compared the composition and diversity of root endophytic fungi from different plants and different sites, with emphasis on special fungal taxa such as DSE. (3) Conclusions: The composition and diversity of cultural endophytic fungi are significantly different in the two alpine medicinal plant species and across various locations. Some fungi showed the preferences of the host or environment. The endophytic fungal resources, especially DSE, were very rich in the two alpine medicinal plants, indicating that these fungi may play a crucial role in the ecological adaptation of host plants in harsh environments.

Genome-wide identification and comprehensive analysis of the FtsH gene family in wheat.

The filamentation temperature-sensitive H (FtsH) gene family, which is known to play a critical role in plant growth and development by regulating photosynthesis, chloroplast development, and response to plant stress, has been extensively studied in various species. However, the FtsH gene family in wheat has not been previously documented. In this study, 38 TaFtsH gene family members were identified, divided into eight groups and unevenly distributed across various chromosomes. Analysis of gene structure and conserved motifs revealed that TaFtsH genes within the same taxon share similar gene structures and conserved motifs. Further collinearity analysis provided insights into the evolutionary history of TaFtsH genes. Examination of cis-acting elements in the promoter region of TaFtsH genes revealed the presence of developmental and stress response elements in genes. The expression pattern of the wheat FtsH gene under various abiotic stresses was analyzed using real-time fluorescence quantitative PCR. Additionally, transient expression in tobacco verified the localization of the TaFtsH11-B protein in chloroplasts. These findings collectively contribute to laying the groundwork for the functional characterization of TaFtsH genes.

Foliar application of zinc oxide (ZnO) nanoparticles ameliorates growth, yield traits, osmolytes, cell viability, and antioxidant system of Brassica juncea (L.) Czern. grown in lead (Pb) stress.

Heavy metal stress is one of the exorbitant problems faced by plants. Lead (Pb) stress is one of the prevalent stressors in agricultural fields. Nanofertilizers are being currently employed for mitigating heavy metal stress in plants. This study assessed the suitability of zinc oxide nanoparticles (ZnONPs) in ameliorating Pb stress in Brassica juncea (L.) Czern. var. Pusa Jagannath. The tested plants were grown in pots using a randomized block design, placed in herbal garden of Jamia Hamdard and treated with different amounts of Pb and nanozinc viz. control (T0), 250 ppm ZnONPs (T1), 500 ppm ZnONPs (T2), 1000 ppm ZnONPs (T3), 250 μM Pb (T4), 500 μM Pb (T5), and theircombinations i.e. 250 μM Pb and 500 ppm ZnONPs (T6), 500 μM Pb and 500 ppm ZnONPs (T7), 250 μM Pb and 1000 ppm ZnONPs (T8) and 500 μM Pb and 1000 ppm ZnONPs (T9). The plants were tested for variations in morpho-physiological parameters, yield traits, biochemical attributes, antioxidant enzyme activity, and cell viability using confocal microscopy. Maximum dose of Pb (500 μM) decreased morphological and yield traits such as leaf area (-51%), shoot length (-17%), root length (-34%), number of seeds per plant (-73%), weight of the seeds (-35%), pod number (-47%), shoot and root fresh weight by -63% and -56%, along with reduction in total chlorophyll (-12%), carotenoid (-38%) content, nitrate reductase (-64%) activity, total soluble protein (-40%), total soluble sugar (-31%) and antioxidant enzymes (SOD, CAT and APX by -14%, -4%, -15% respectively) in comparison to control. Stress markers like proline (195%) and MDA (266%) were elevated in Pb-treated plants.The increased level of total phenol content (89%) and total flavonoid content (478%) was also noted in Pb treated plants which acted as non-enzymatic antioxidant defense. The foliar application of ZnONPs (1000 ppm) was found to be effective in ameliorating Pb induced stress, as depicted by the increases in root length (43%), shoot length (38%), pod number (46%), seed weight (70%), number of seeds per plant (105%), chlorophyll content (41%), carotenoid content (28%), total soluble protein content (20%), and nitrate reductase activity (59%) in comparison to control. When ZnONPs (1000 ppm) was supplemented in Pb (250 μM) treated plants, antioxidant enzymes (SOD and CAT increased by 83%, and APX by 75%) and stress markers such as proline amplified by 387%, and total soluble sugar (61%), with respect to control. ZnONPs also improved the cell viability under Pb stress as revealed by confocal microscopy. In summary, foliar spray of ZnONPs proved effective in mitigating the Pb-induced stress in mustard which could be an effective strategy to alleviate the deleterious effects of Pb stress (500 μM) in mustard plants so as to realize its sustainable production under abiotic stress.

Green synthesized silicon dioxide nanoparticles (SiO2NPs) ameliorated the cadmium toxicity in melon by regulating antioxidant enzymes activity and stress-related genes expression

Green synthesized nanoparticles (NPs) are an eco-friendly and cost-effective approach to reduce heavy metal stress in plants. Among heavy metals, cadmium (Cd) possesses higher toxicity to the crops and ultimately reduces their growth and yield. The current study aims to evaluate the effectiveness of green synthesized SiO2NPs to reduce toxic effects of Cd in melon (Cucumis melo) by regulating physiological parameters, enhancing antioxidant enzyme activity, and modulating stress-related gene expression. The SiO2NPs were synthesized using Artemisia annua plant extract having spherical shape and size within the range of 40-70 nm and characterized using advanced spectroscopic and analytical techniques. The application of SiO2NPs (75mg/L) significantly improved physiological parameters such as shoot length (SL), root length (RL), leaf fresh weight (LFW), root fresh weight (RFW), leaf dry weight (LDW) and root dry weight (RDW) by 14%, 20%, 15%, 16%, 14%, and 28%, respectively, compared to Cd-stressed plants. Photosynthetic pigments (chlorophyll and carotenoids) showed a notable increase of 15% and 40%, respectively. Furthermore, the activities of antioxidant enzymes such as SOD, POD, CAT, and APX were enhanced by 28.67%, 35.45%, 32.07%, and 42.75%, respectively. In addition, applying SiO2NPs increased the concentration of macronutrients N, P, and K by 33%, 40%, and 37%, respectively, compared to Cd-stressed plants. Moreover, SiO2NPs upregulated the expression of several stress-related genes and reduced Cd accumulation in shoots and roots. This study reveals that green synthesized SiO2NPs effectively reduced the Cd toxicity in melon by improving morphological and physiological parameters, enhancing antioxidant enzyme activity, and regulating the expression of stress-related genes. These findings suggest that green synthesized SiO2NPs could play a crucial role in sustainable agriculture by protecting crops from heavy metal stress.

Impact of water stress to plant epigenetic mechanisms in stress and adaptation.

Water is the basic molecule in living beings, and it has a major impact on vital processes. Plants are sessile organisms with a sophisticated regulatory network that regulates how resources are distributed between developmental and adaptation processes. Drought-stressed plants can change their survival strategies to adapt to this unfavorable situation. Indeed, plants modify, change, and modulate gene expression when grown in a low-water environment. This adaptation occurs through several mechanisms that affect the expression of genes, allowing these plants to resist in dry regions. Epigenetic modulation has emerged as a major factor in the transcription regulation of drought stress-related genes. Moreover, specific molecular and epigenetic modifications in the expression of certain genetic networks lead to adapted responses that aid a plant's acclimatization and survival during repeated stress. Indeed, understanding plant responses to severe environmental stresses, including drought, is critical for biotechnological applications. Here, we first focused on drought stress in plants and their general adaptation mechanisms to this stress. We also discussed plant epigenetic regulation when exposed to water stress and how this adaptation can be passed down through generations.

In silico analysis of trehalose biosynthesis genes provides clues to reveal its roles in Avicennia marina adaptation to tidal submergence.

Trehalose has an important function for alleviating various abiotic stress in plants. Nevertheless, the functional and evolutionary characteristics of trehalose biosynthesis genes in mangrove plants is not documented. Here, using typical mangrove Avicennia marina, we found the trehalose content decreased in the roots and leaves and T6P increased significantly in the leaves under tidal submergence. Then, the basic physicochemical properties and gene structure of trehalose biosynthesis genes (AmTPS and AmTPP), and the conserved domain and motifs of AmTPS and AmTPP proteins were analyzed. The collinearity analysis and Ka/Ks values indicated that AmTPS and AmTPP are evolutionarily conserved. Tissue-specific expression profiling showed that most AmTPS and AmTPP genes have tissue specificity. RNA-Seq analysis showed that five AmTPS genes were markedly up-regulated in A. marina treated with tidal submergence. Subcellular localization analysis revealed three genes including AmTPS10B, AmTPS11A and AmTPS11C out of these five up-regulated AmTPS genes work in plasma membrane, cytoplasm and nucleus. Finally, integrative analysis of bioinformatics and RNA-Seq analysis were performed to excavate transcription factors that may regulate AmTPS and AmTPP genes in A. marina response to submergence. Taken together, these findings provide new insights into the response to tidal submergence in A. marina at the aspect of trehalose.

The paradoxical effects of beneficial bacteria on Solanum lycopersicum under Cd stress.

This study investigated the complex interactions between a novel consortium and tomato seedlings under cadmium (Cd) stress. The consortium consists of two bacteria, Pseudomonas sp. HS4 and Paenarthrobacter sp. AS8, both with proven plant growth-promoting (PGP) properties, isolated from Cd hyperaccumulators. Our research highlights the paradoxical effects of these bacteria, revealing their dual role in reducing Cd uptake while simultaneously inducing oxidative stress in plants. Hydroponic experiments showed that the consortium reduced Cd accumulation in tomato shoots by 52% compared to uninoculated controls. However, this reduction was accompanied by decreased plant biomass and increased oxidative stress, with malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) levels up to 80% and 160% higher, respectively, in inoculated plants. Root H₂O₂ production increased by 38% under 50μM Cd without a corresponding rise in catalase (CAT) activity. Despite Cd exposure, the consortium promoted chlorophyll and carotenoid synthesis, restoring pigment levels to those of unstressed controls. Gene expression analysis revealed a complex impact on stress responses, with inoculation suppressing Sl1 gene expression in roots and upregulating the oxidative stress-related GR-1 gene in shoots. These findings highlight the complex and multifaceted relationship between beneficial bacteria and plant fitness under heavy metal stress, with significant implications for sustainable agriculture. The study raises new questions regarding the broader physiological and ecological impacts of applying hyperaccumulator-associated bacteria in crop management, emphasizing the necessity for deeper mechanistic insights into these interactions to fully harness their potential in improving crop resilience and productivity.

A high temperature responsive UDP-glucosyltransferase gene OsUGT72F1 enhances heat tolerance in rice and Arabidopsis.

OsUGT72F1 enhances heat tolerance in plants by improving ROS scavenging and modifying multiple metabolic pathways, under the regulation of transcription factors OsHSFA3 and OsHSFA4a. High temperature is one of the most critical environmental constraints affecting plant growth and development, ultimately leading to yield losses in crops such as rice (Oryza sativa L.). UDP (uridine diphosphate)-dependent glycosyltransferases (UGTs) are believed to play crucial roles in coping with environmental stresses. However, the functions for the vast majority of UGTs under high temperature stress remain largely unknown. In this study, we isolated and characterized a high temperature responsive UDP-glycosyltransferase gene OsUGT72F1 in rice. Our findings demonstrated that overexpression of OsUGT72F1 enhanced heat-stress tolerance, while the mutant plants displayed a sensitive phenotype under the same stress conditions. Ectopic expression of OsUGT72F1 in Arabidopsis thaliana also conferred improved heat tolerance to the plants. Further investigation revealed that OsUGT72F1 reduced the generation of reactive oxygen species (ROS) and boosted the activity of antioxidant enzymes, thereby alleviatingoxidativedamage under heat-stress conditions. Moreover, transcriptomic analysis indicated that the action of OsUGT72F1 leads to the upregulation of multiple metabolic pathways including phenylpropanoid biosynthesis, zeatin biosynthesis, and flavonoid biosynthesis. In addition, the upstream regulatory mechanism of the OsUGT72F1 gene has been identified. We found that the transcription factors OsHSFA3 and OsHSFA4a can bind to the OsUGT72F1 promoter and enhance its transcription level. Together, this study revealed that the glycosyltransferase gene OsUGT72F1 plays a vital role in the adaptive adjustment of high temperature stress in plants, revealing a new heat tolerance pathway and providing a promising gene candidate for the breeding of heat-resistant crop varieties.

Synergistic mechanisms for efficient and safe antibiotic removal: Effective adsorption and photocatalytic degradation using aerogels

To tackle the issues of low adsorption capacity, poor regeneration efficiency, and limited recoverability in wastewater treatment adsorbents, we innovatively developed a low-cost Fe(III)-SA gel ball aerogel (FA) through a simple chemical crosslinking method. FA aerogel exhibits exceptional adsorption performance for a wide range of antibiotics, including norfloxacin (NOR), ciprofloxacin (CIP), and tetracycline hydrochloride (TC), showcasing its broad applicability. Remarkably, FA achieved a maximum NOR adsorption capacity of 338.4 mg/g (Langmuir isotherm model, pH 7.0, 298 K, m/V=0.1 g/L). Furthermore, under the synergistic effect of photocatalysis, FA demonstrated a breakthrough by removing 97 % of NOR (30 mg/L, 50 mL) within just 150 min. Notably, FA displayed innovative regeneration capabilities, successfully completing 10 continuous and stable NOR removal cycles without loss of performance. The DFT calculations alongside experimental evidence were employed to elucidate the NOR degradation pathway, while electron density distribution and Fukui function analysis confirming the proposed degradation pathways through HPLC-MS results. Moreover, plant stress and zone of inhibition tests verified that the degradation intermediates were significantly less toxic, ensuring the safety of the regeneration process. This research introduces an innovative approach for designing superior adsorbents and provides critical insights into efficient and sustainable adsorbent regeneration.

Microplastics and Dechlorane Plus co-exposure amplifies their impacts on soybean plant.

The co-existence of microplastics (MPs) and organic pollutants on agricultural ecosystems pose potential implications for both food safety and environmental integrity. The combined effects of MPs with Dechlorane Plus (DP), a newly listed banned flame retardant, remain unknown. This study explores the biological responses of soybean plants to exposure from polyethylene (PE) and polyvinyl chloride (PVC) MPs and DP. Results showed that combined exposure altered the activity of antioxidant enzymes and inhibited the growth of soybean plants, compared with DP or MPs exposure alone. DP markedly reduced both the root length and root weight of soybean plants in a dose-dependent manner. Proteomics profiling suggests that PE interacts with protein translation and modification pathways, particularly via the regulation of heat shock protein binding. High concentration DP (HDP) treatment group enhances the plant's stress resistance by regulating relevant proteins through the modulation of hydrogen peroxide catabolic protein expression and the formation of water channel proteins. In the combined treatments, low concentration DP with PVC triggered increased protein expression related to photosynthesis response, further demonstrating the enhanced inhibitory effects. This study for the first time maps the changes in the physiological and the molecular mechanisms of the impacts on higher plant caused by MPs and DP co-exposure.